TEXAS WASTEWATER EXAMINATION REAL EXAM
VERSIONS A AND B | EACH CONTAINS 2 ACCURATE
TESTED REAL EXAMS AND A TEST BANK FOR EACH |
PERFECT STUDY PACK | GRADED A | GUARANTEED PASS |
LATEST EDITION
A primary clarifier has a flow of 3.0 MGD and has a diameter of 100 feet. It is 12 feet deep and
has 24 inches of freeboard. What is the detention time in hours?
Formulas
Anaerobic digester gas should contain?
65-75% methane, 25-35% carbon dioxide and 1-5% nitrogen.
An activated sludge plant has an average daily flow of 3.5 MG. The aeration tank capacity is 1.2
MG with a MLSS concentration of 3200 mg/L. The clarifier has a capacity of 400,000 gallons
with a MLSS concentration of 6,000 mg/L. The wasting rate is 40,000 gallons per day with a
MLSS concentration of 8, 000 mg/L. The effluent TSS is 18 mg/L. Assuming volatile
concentrations of 70%, what is the MCRT and what type of activated sludge plant should this
be?
Formulas MCRT
What are some of the causes of filaments in the aeration basin?
a. low DO
b. low organic loading
c. septic wastes
d. nutrient deficiencies .
e. high sulfur content
Good sludge quality will have a predominance of what organisms in the MLSS?
Ciliated protozoa
When an RBC is operating correctly, how will the slime appear on the media?
Grey to brown 0.05 to 0.1 inches thick
According to design criteria, what are the minimum allowable diameters for a manhole?
24 inch opening and 48 inch inside diameter
What activated sludge process does not achieve complete nitrification?
Contact Stabilization
In the selection of forced main wastewater piping, what is the minimum working pressure?
,150 psi
The oxygen depletion of BOD dilution water should not exceed
0.2 mg/L.
What is the minimum air gap when making water and wastewater connections?
Minimum of one inch or twice the inlet pipe size whichever is greater.
What is the minimum useful size pipe to prime a centrifugal pump?
1 inch
An anaerobic digester must maintain an average year round temperature of
95 degrees F.
How do you remove shoring from a trench?
From the bottom up
Which of the following methods would you use to increase the degree of nitrification in an
activated sludge plant?
increase dissolved oxygen levels and increase the sludge age
Which of the following are considered normal operator controls on an activated sludge plant?
aeration rates return and wasting rates
Reducing the return sludge flow rate for an activated sludge system which has a good settling
sludge will ________.
increase the RAS concentration and the clarifier sludge blanket thickness
An extended air activated sludge plant has a fast settling sludge and high amounts of pin floc
leaving the clarifier. One way to correct this problem is to ________.
* reduce the MCRT by wasting more
* increase the F/M ratio by wasting more
The primary causes of wastewater stoppages are ________.
roots and grease
The inside diameter of a manhole must be how wide?
48 inches
On a construction job site, equipment booms must maintain at least how many feet of clearance
from overhead electric lines?
10 feet
,Digester gas should contain about ________.
a. 65% - 75% methane
A treatment plant has two primary clarifiers. Each has a diameter of 40 feet and a depth of 12
feet. If the design flow is 1.2 mgd, find the surface loading on each clarifier in gallons/ft2/day.
Assume the flow is equally split between the two clarifiers.
3.14 x 20 x 20 = 1256
1,200,000 /2
= 600,000 gallons each
600,000/ 1256
b. 478 gallons/ft2/day
Distilled water used for the BOD analysis should not exceed ________.
0.2 mg/L depletion
What is TCEQ doing to control "point source" pollution of the Texas waterways?
*Permitting of domestic wastewater plants
*Permitting of industrial wastewater plants
Describe proper design of force main wastewater lines.
Minimum two fps velocity with the smallest pump operating alone. Minimum four inch diameter
pipe with 150 psi rating.
What is Standard Dimension Ratio?
Ratio of outside pipe diameter (OD) to wall thickness (PVC)
Describe proper design of gravity wastewater lines.
Designed to flow half full ,under normal conditions, at a minimum of two fps and a maximum of
ten fps.
Manholes should have a minimum opening of?
24 inches and be at least 4 feet wide.
pH meters should be calibrated how often? What standards should be used for calibration
purposes?
Daily with at least two buffers.
What is the standard chlorine residual and minimum contact time on Texas wastewater permits?
a. 1.0 mg/L for a minimum 20 minutes detention time at peak flow b. No chlorine residual
needed if detention time is greater than 21 days
, As the complexity of an organization increases, what management function becomes most
important?
Planning
What is the effective chlorine disinfecting agent?
Hypochlorous Acid (HOCl)
Does pH affect the chlorination process? Explain your answer.
When using free chlorine the disinfectant is HOCl acid. As such it is much more effective at pH's
below 7.0. Above 7.0 pH the acid begins to be neutralized.
What is the effluent chlorine residual in Texas that is standard on permits and the minimum
detention time? What is the maximum residual allowed?
Texas standard is 1.0 mg/L for a minimum 20 minutes detention time at peak flow. Maximum
residual allowed is 4.0 mg/L.
A treatment plant has a clarifier that is 60 feet in diameter and is 10 feet deep. The weir is 2 feet
inside the outer clarifier wall. The flow is 1.0 MGD. The weir and outflow channel is 3 feet deep.
a. What is the detention time in hours?
Formula
What activated process cannot nitrify in a single stage?
Contact Stabilization
What is the GPM output of a piston pump with an 8-inch diameter piston with a 10-inch stroke
operating at 50 strokes per minute?
Formula
A treatment plant has a clarifier that is 60 feet in diameter and is 10 feet deep. The weir is 2 feet
inside the outer clarifier wall. The flow is 1.0 MGD. The weir and outflow channel is 3 feet deep.
a. What is the detention time in hours?
b. What is the surface loading in gal/ft2/day?
c. What is the weir loading in gal/linear ft/day?
Formulas
One element of being an effective communicator is to ________.
a. be a good listener
In order to promote a collaborative management style, one thing a supervisor can do is
________.
join the team as a member rather than as boss
VERSIONS A AND B | EACH CONTAINS 2 ACCURATE
TESTED REAL EXAMS AND A TEST BANK FOR EACH |
PERFECT STUDY PACK | GRADED A | GUARANTEED PASS |
LATEST EDITION
A primary clarifier has a flow of 3.0 MGD and has a diameter of 100 feet. It is 12 feet deep and
has 24 inches of freeboard. What is the detention time in hours?
Formulas
Anaerobic digester gas should contain?
65-75% methane, 25-35% carbon dioxide and 1-5% nitrogen.
An activated sludge plant has an average daily flow of 3.5 MG. The aeration tank capacity is 1.2
MG with a MLSS concentration of 3200 mg/L. The clarifier has a capacity of 400,000 gallons
with a MLSS concentration of 6,000 mg/L. The wasting rate is 40,000 gallons per day with a
MLSS concentration of 8, 000 mg/L. The effluent TSS is 18 mg/L. Assuming volatile
concentrations of 70%, what is the MCRT and what type of activated sludge plant should this
be?
Formulas MCRT
What are some of the causes of filaments in the aeration basin?
a. low DO
b. low organic loading
c. septic wastes
d. nutrient deficiencies .
e. high sulfur content
Good sludge quality will have a predominance of what organisms in the MLSS?
Ciliated protozoa
When an RBC is operating correctly, how will the slime appear on the media?
Grey to brown 0.05 to 0.1 inches thick
According to design criteria, what are the minimum allowable diameters for a manhole?
24 inch opening and 48 inch inside diameter
What activated sludge process does not achieve complete nitrification?
Contact Stabilization
In the selection of forced main wastewater piping, what is the minimum working pressure?
,150 psi
The oxygen depletion of BOD dilution water should not exceed
0.2 mg/L.
What is the minimum air gap when making water and wastewater connections?
Minimum of one inch or twice the inlet pipe size whichever is greater.
What is the minimum useful size pipe to prime a centrifugal pump?
1 inch
An anaerobic digester must maintain an average year round temperature of
95 degrees F.
How do you remove shoring from a trench?
From the bottom up
Which of the following methods would you use to increase the degree of nitrification in an
activated sludge plant?
increase dissolved oxygen levels and increase the sludge age
Which of the following are considered normal operator controls on an activated sludge plant?
aeration rates return and wasting rates
Reducing the return sludge flow rate for an activated sludge system which has a good settling
sludge will ________.
increase the RAS concentration and the clarifier sludge blanket thickness
An extended air activated sludge plant has a fast settling sludge and high amounts of pin floc
leaving the clarifier. One way to correct this problem is to ________.
* reduce the MCRT by wasting more
* increase the F/M ratio by wasting more
The primary causes of wastewater stoppages are ________.
roots and grease
The inside diameter of a manhole must be how wide?
48 inches
On a construction job site, equipment booms must maintain at least how many feet of clearance
from overhead electric lines?
10 feet
,Digester gas should contain about ________.
a. 65% - 75% methane
A treatment plant has two primary clarifiers. Each has a diameter of 40 feet and a depth of 12
feet. If the design flow is 1.2 mgd, find the surface loading on each clarifier in gallons/ft2/day.
Assume the flow is equally split between the two clarifiers.
3.14 x 20 x 20 = 1256
1,200,000 /2
= 600,000 gallons each
600,000/ 1256
b. 478 gallons/ft2/day
Distilled water used for the BOD analysis should not exceed ________.
0.2 mg/L depletion
What is TCEQ doing to control "point source" pollution of the Texas waterways?
*Permitting of domestic wastewater plants
*Permitting of industrial wastewater plants
Describe proper design of force main wastewater lines.
Minimum two fps velocity with the smallest pump operating alone. Minimum four inch diameter
pipe with 150 psi rating.
What is Standard Dimension Ratio?
Ratio of outside pipe diameter (OD) to wall thickness (PVC)
Describe proper design of gravity wastewater lines.
Designed to flow half full ,under normal conditions, at a minimum of two fps and a maximum of
ten fps.
Manholes should have a minimum opening of?
24 inches and be at least 4 feet wide.
pH meters should be calibrated how often? What standards should be used for calibration
purposes?
Daily with at least two buffers.
What is the standard chlorine residual and minimum contact time on Texas wastewater permits?
a. 1.0 mg/L for a minimum 20 minutes detention time at peak flow b. No chlorine residual
needed if detention time is greater than 21 days
, As the complexity of an organization increases, what management function becomes most
important?
Planning
What is the effective chlorine disinfecting agent?
Hypochlorous Acid (HOCl)
Does pH affect the chlorination process? Explain your answer.
When using free chlorine the disinfectant is HOCl acid. As such it is much more effective at pH's
below 7.0. Above 7.0 pH the acid begins to be neutralized.
What is the effluent chlorine residual in Texas that is standard on permits and the minimum
detention time? What is the maximum residual allowed?
Texas standard is 1.0 mg/L for a minimum 20 minutes detention time at peak flow. Maximum
residual allowed is 4.0 mg/L.
A treatment plant has a clarifier that is 60 feet in diameter and is 10 feet deep. The weir is 2 feet
inside the outer clarifier wall. The flow is 1.0 MGD. The weir and outflow channel is 3 feet deep.
a. What is the detention time in hours?
Formula
What activated process cannot nitrify in a single stage?
Contact Stabilization
What is the GPM output of a piston pump with an 8-inch diameter piston with a 10-inch stroke
operating at 50 strokes per minute?
Formula
A treatment plant has a clarifier that is 60 feet in diameter and is 10 feet deep. The weir is 2 feet
inside the outer clarifier wall. The flow is 1.0 MGD. The weir and outflow channel is 3 feet deep.
a. What is the detention time in hours?
b. What is the surface loading in gal/ft2/day?
c. What is the weir loading in gal/linear ft/day?
Formulas
One element of being an effective communicator is to ________.
a. be a good listener
In order to promote a collaborative management style, one thing a supervisor can do is
________.
join the team as a member rather than as boss
